Switching device.



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SW-ICHING DEVECE.

Specification of Letters Patent.

lApplication filed October 7, 1908. Serial No. 4561513.

and State of Pennsylvania, have invented a new and useful Improvement inSwitching "Devices, of which the followingis av specification.

My invention relates to switching devices .and it has special referenceto knife-blade switches..

The 'object of my invention is to provide simple and inexpensive meanswhich 'shall automatically open a knife-blade switch, in the event'ofafailure oi' thevoltage of the circuit in which it is included, and whichshall not interfere with the manual manipulation o t the switch.

Automatic circuit `inerrupters of various types and sizes haveheretofore been constructed for the purpose of automaticallyinterrupting electric circuits under predeter-` mined conditions, suchas overload, under-A load and novoltage rThese devices,how

ever, are relatively complicated and expensive, as compared with thevusual forms of imite-blade switches which are manually operated.Knife-blade switches are obviously unsuitable for interrupting a circuitwhich is traversed by relatively large currents or high voltages, onaccount of the detrimental eii'ect of electric arcs on such devices.

it is sometimes desirable to utilize a switching device which willAautomatically interrupt the circuit upon the failure of the line voltageand,A according to my present invention, I provide a very simpleactuating mechanism which is adapted for use 'with knifablade switchesof the usual type and' Referring to Figs. `1 `and 2 of the drawging, thedevice here illustratedv comprises. a fdouble pole knife-blade switch .1which is mounted, in the-usual manner, upon a slab {or base 2 of theinsulating material and an lautomatic actuating mechanism 3 therefor,'of which the operation of theknife blade .switch is normallyindependent.l The switch proper maybe constructed in any suitablemanner-and may be provided with one or rammed Aug. 5,1913.

more poles, within the scope of my invention, the switch illustratedbeing composed of four 'stationary contact members 4, 5, 6, and 7, apair of switch blades 8 and 9 that are pivotally mounted on thestationary contact members 4 and '5 and are adapted to engage thecontact members Gand 7, an interconnecting or spacing block 10 ofinsulating material and an operatinghandle 11 secured thereto. v

The-actuating mechanism 3 comprises a twopart lever 12 pivotallymounted, atene end, on a' pin shaft 13, in alinement with the switchblade pivots, a lever 14, a pair of con- -necting links 15 and anelectro-magnet 16 having a coil 17, a stationary core member 18 and amovable Vcore member or armature 19 one end of which is rigidlyconnected to move the armature downward, such as the magnetiopull whenthe coil is energized, holds the long arms of the lever substan-` tiallyin the vertical position in which manual manipulation of the-switch ispermitted.

The stationary core member is supported in a box or bracket 2O which issecured to the insulating slab or base2 and the outer edge of this boxis provided with pins 21 to which are attached the lower ends of springs22, the upper ends of said springs being attached to the Vlong arms ofthe lever 12 which are adapted to 'engage the spacing block 10. Thetensionin the springs, whenlthe switch is closed, is suicient to openthe switch and interrupt the circuit when the electro-magnet isdenergized.

Referringv to Fig. 3,. as here-shown, the switch blades are interposedin the respective sides of an electric circuit 23-24 and the coil4 17 ofthe electro-magnet is connected across said circuit. This coil ,isconse- .the line voltage fails; will be .denergzed With this,arrangement, the 'actuating' lever will normally be held in'such aposition that the switch may -be freely opened and closed. In some casesit may, however, bedesirable to connect` the coil of the magnet to thedistributing circuit on lthe other side of the switch. With thisarrangement,- the coil will always be denergized as soon as the' switchis opened and the actuating lever will follow the switch blade Wheneverthe switch is manually operated. The automatic operation of vthe switchwill l be the same-in either case.

It is to be understood that' various structural modifications may beeffected Wit-hin in which case the coil the scope of my invention, asdened in the appended claim.

claim as my invention: The combination with a., me, siede switch9 themovable member of which is orf mally unrestrained except hy. ricticn hev tween jaw and blade, of -a lever and a spring 'for forcing saidmovable lmeriiier to spew- FORD W. HARRIS.

Witnesses: 1

.FRED W. CLoUD, BIRNEY HINES.

